The present invention generally relates to an energy storage device for a vehicle and, more particularly, to a propeller shaft and energy storage assembly.
In view of recent events, fuel economy for automotive vehicles has become of great importance. Environmental concerns and governmental emissions regulations are also becoming pressing issues for automobile manufacturers. These and other considerations have driven manufacturers of automotive vehicles to consider alternate fuel sources such as solar power, fuel cells and natural gas. Battery powered and hybrid vehicles combining various power transmission techniques are also among a host of other concepts being evaluated.
Some vehicle manufacturers have also addressed the energy efficiency challenge by creating vehicles that weigh less and more efficiently cut through the air as they travel. While many of these devices and concepts have merit, opportunities exist for alternate designs.
One solution presently contemplated includes a propeller shaft and energy storage assembly having a propeller shaft with a first end adapted to be drivingly coupled to an engine and a second end adapted to be drivingly coupled to a driven wheel. The propeller shaft and energy storage assembly includes a first power transfer mechanism for selectively drivingly interconnecting the propeller shaft and an energy storage device when a vehicle is moving forward. A second power transfer mechanism is operable to selectively retain and release energy stored within the energy storage device. A third power transfer mechanism selectively drivingly interconnects the energy storage device and the propeller shaft when vehicle acceleration is desired. The release of the stored energy through the propeller shaft then assists the engine or other power source in accelerating the vehicle.
Another propeller shaft and energy storage assembly includes a propeller shaft having a first end adapted to be drivingly coupled to an engine and a second end adapted to be drivingly coupled to a driven wheel. The propeller shaft and energy storage assembly includes a first clutch selectively operable to drivingly interconnect the propeller shaft and a spring to store energy in the spring, a second clutch operable to restrict movement of the spring to retain the stored energy within the spring and a third clutch operable to selectively drivingly couple the spring and the propeller shaft to transfer the stored energy through the propeller shaft.
Furthermore, a method of storing and releasing energy in a vehicle including an engine drivingly coupled to a driveline where the driveline has a propeller shaft and an energy storage device is disclosed. The method includes placing the vehicle in motion and drivingly coupling the propeller shaft to the energy storage device to transfer energy from the moving vehicle to the energy storage device. The method also includes de-coupling the propeller shaft from the energy storage device and retaining the stored energy in the energy storage device. The energy from the energy storage device is then transferred to the propeller shaft by drivingly coupling the energy storage device with the propeller shaft to assist in accelerating the vehicle.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.